transition from rock revetment to sedimentary bottom is distinct, 

 primarily because of a contrast in slope of the two substrate types. 



The north- and south-side talus beds are intermediate in size 

 between those of the west and east sides. The upper and lower mar- 

 gins are highly irregular on both the north and south sides. Some 

 "fingers" of talus extend more than 3 meters up the north-side re- 

 vetment, and an isolated shallow pocket of talus exists in a flat 

 area about half way down the side near the location of the permanent 

 transect. The sediment lying near the base of the island on both the 

 north and south sides is inclined, possibly because it overlies a 

 buried part of the talus bed. Many isolated rocks punctuate the 

 natural bottom sediment, particularly along the north side. Shells 

 of the bivalves, Pododesmus cepio (jingles), Hinnites multirugosus 

 [rock scallop), and unidentified species form the bulk of the talus 

 beds on the north and south sides. Some Mytilus talus exists near 

 the west end of the north side which may have been carried around 

 from the west side by currents. Biota frequently encountered in 

 association with the talus beds include the tube worm, Diopatra 

 ornata; the tube anemone, Pachycerianthus sp; the nudibranch, 

 Dendrodoris fulva; the whelk, Kelletia kelletii; the bat star, 

 Patiria miniata; and hermit crabs including Pagaristes ulreyi and 

 Isocheles pilosus. 



3. Analysis of Seasonal Data from Permanent Transects . 



An overview of the vertical distribution of tentatively discrimi- 

 nated major species associations, synthesized from data of the first 

 two seasonal permanent transect surveys (summer and fall, 1976) is 

 graphically represented for each side of the island in Figures 13 to 

 16. Figures 17 to 20 augment information provided in Figures 13 to 

 16 by illustrating the vertical distributions of selected dominant 

 raacrobiota over the permanent transects. A broad vertical pattern 

 for Patiria miniata is apparent on all sides. Also noteworthy is the 

 dominance of the Lithothamnium-Lithophyllum complex over the upper 

 reaches of all but the east side. The east side also appears unique 

 in that distributions of several species are much less restricted 

 vertically than is the case on the other sides (e.g., the red algae, 

 Veleroa subulata-Murrayellopsis dawsonii complex and the abundant 

 ectoproct, Lagenipora punctulata) . 



A total of 250 taxa of macrobiota was identified during the four 

 seasons of the permanent transect sampling program. These taxa are 

 listed in Table 1 together with information on which side of the is- 

 land each occurred. The species occurring in transects on all four 

 sides of the island may be regarded as ubiquitous and generally the 

 dominant macrobiota over the entire island. Many of the species listed 

 in Table 1 undoubtedly occur on more sides of the island than indi- 

 cated. An example is the giant kelp, Macrocystis sp. Kelp is most 



39 



